Our invention relates to an indicator circuit, and particularly to an indicator circuit that shows the operation and battery voltage of a radio transmitter by a single lamp.
Users of battery powered personal or portable radio transmitters need to know the condition or state of the battery charge so that the battery can be replaced or recharged at the proper time. While a voltmeter can be used to indicate the battery voltage and hence its charge condition, such a meter is relatively expensive and fragile.
Accordingly, a primary object of our invention is to provide a new and improved circuit for indicating the condition or state of battery charge in a personal or portable radio transmitter.
The Federal Communications Commission requires that an indicator lamp be provided in some applications of personal or portable radio transmitters so that the user will have a visual indication of when the transmitter is operated.
Accordingly, another object of our invention is to provide a new circuit that utilizes the required operating indicator lamp of a personal or portable radio transmitter to further indicate the state or condition of the transmitter battery charge.